Question

More specificly the html tag is left unclosed in the edit view when edit is under mod_perl. When edit is removed from mod_perl the page finishes fine (the tag is closed).

The error indication looks like this at bottom of edit view:

</htm

• TWiki version: 03 Aug 2002 beta
• Web server: Apache/1.3.26 (Unix) mod_perl/1.27 mod_ssl/2.8.10 OpenSSL/0.9.6a
• Server OS: FreeBSD 4.6-STABLE
• Web browser: IE 6.0
• Client OS: XP/Home
• testenv

-- DrewCard - 12 Aug 2002

PS - Got an Internal Server Error on my previous preview of this topic... there - I got is again. Back and re-preview it goes fine.

Answer

Not sure. Could this be a some kind of race condition? E.g. the script pumps the HTML content to stdout; the browser returns the content before it finishes reading? Try to disable buffering, e.g. in the view script remove the comment of:

#$| = 1;                  # no buffering

The Internal Server Error is sometimes produced by the SF server, has nothing to do with the TWiki script or the content of this topic.

-- PeterThoeny - 13 Aug 2002

BTW the $| variable should probably be declared with local - see comment in testenv and the mod_perl docs for the details. Also, I vaguely recall the Apache docs or FAQ having something on this issue, to do with the way that sockets must be closed to avoid truncating things.

-- RichardDonkin - 13 Aug 2002

As I tried to explain above this only occurs in edit. Makeing the buffering change above to view did not change anyting I could see.

Now that I have modified my template to include a comment after the ;lt&/html;gt& the comment is not getting closed properly, the '->' is geting cut off.

-- DrewCard - 13 Aug 2002

I also get the same error. It disappears when I disable mod_perl. It also occurs only on edit pages.

• TWiki version: 03 Aug 2002 beta
• Web server: Apache/1.3.26 (Unix) mod_perl/???
• Server OS: HPUX 11.11
• Web browser: IE 5.5 SP 2
• Client OS: Win2K

-- CharlesLacz - 08 Sep 2002

In the edit script, did you try to add:

$| = 1;

just before:

$query = new CGI;

I am not a mod_perl expert, but worth a try.

-- PeterThoeny - 09 Sep 2002

I did try adding $| = 1; and local $| = 1; to the edit script and neither made any difference. I installed Mozilla 1.1 yesterday and the problem doesn't occur on that browser at all. I'd still want to fix it since most people here use IE.

-- CharlesLacz - 11 Sep 2002

Have a look at IncompletePagesOnTWikiBeta15March2001 - this looks somewhat similar, although it was happening on the view page. That page has some debugging ideas, including the use of tcpdump, which should be included on FreeBSD. When I had that problem, I proved that TWiki was generating the full page but the problem ended up going away before I solved it.

Are you using any proxies? If so, try turning them off. Also, try turning off HTTP/1.1 and other features in IE.

Does this happen under CGI rather than mod_perl? Since Edit is not very frequent, you might just turn off mod_perl for editing as a temporary measure - see SelectiveModPerl.

Most TWiki users are probably using IE, so it's probably some subtle interaction of the browser, Apache, mod_perl and possibly TWiki. You might also like to check the mod_perl site and to post to a mod_perl email list to see if they've seen this.

-- RichardDonkin - 15 Sep 2002

This was most probably fixed in ExtraneousLineInHttpHeader - the problem was introduced by the fix to BackFromPreviewLosesText (mea culpa...)

-- RichardDonkin - 29 Aug 2003

Just to confirm that ExtraneousLineInHttpHeader seems to be the solution. I had the same issue, where it would also frequently trigger authentication errors under IE6, intermittently under IE5.5, but Mozilla and Lynx would display fine. It was driving me nuts yesterday trying to figure it out...!

Thanks

-- EdWildgoose - 10 Sep 2003

Thanks for the feedback, I've updated KnownIssuesOfTWiki01Feb2003.

-- RichardDonkin - 10 Sep 2003